Making waves

[varjohaltia]

Spectrum2, originally uploaded by Varjohaltia.

Having borrowed a spectrum analyzer, I checked to see what's in the air in my home. Good grief. The top of the graph is -30 dBm. -70 dBm is still a perfectly useful wireless signal. Needless to say, with all this ruckus, no wonder said signal won't make it through!

Comments

[kaote.livejournal.com]

Whoa now, where do you get a spectrum analyzer!? How neat.

Someone moved in next to me whose frequency made my wireless mouse not want to work all the time. It would be interesting to see the range already occupied...

[varjohaltia.livejournal.com]

A sales rep "forgot" it at work, and won't be coming back to pick it up for a week or two. It's really nifty. It's really just a card-bus card (a $4000 one) that does all the hard work, and extremely cool software to go with it. In the graph above, the yellow is essentially a short-time max, the blue line is cumulative. What the cumulative line kind of hides is that tooth pattern visible on the right throughout the entire spectrum. The analyzer fingerprinted it as a Dect-compatible cordless phone. The rest of it is microwaves and some half dozen access points in the surrounding units. The thing lets you massage and display the data in all manner of ways, does three frequency bands (simultaneously), and has some nice "intelligence" features that tell you what's happening based on heuristics and RF fingerprints. We'll see if there's any hope to eventually get one. We've had a dire need for something like this for years now. (The one we currently can borrow from another department is based on CRT display, is the size and weight of a sowing machine, and requires a long extension cord to be mobile and two people to carry all the assorted hardware around. I wouldn't be surprised if it had tubes in it.)